1. Field of the Invention
This application relates to electrical cutting devices for use in laparoscopic surgery.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
This invention provides an electrotome which is inserted transcutaneously through a standard laparoscopic port or trocar. The electrotome cuts by rotating a heated electrical loop. The size of the loop is adjusted by the user to control the depth of the cut, as, for example, for resection of renal adenomas. The electrotome also is used to grasp the resected tissue for removal through the trocar for pathological examination.
U.S. Pat. No. 4,060,087 discloses a TIF resectoscope in which HF current is applied to two parallel semi-circular loop electrodes. One electrode is neutral and one live. This improvement avoids the use of a single live electrode cutter with the patient grounded, an arrangement sometimes causes burns in the urethra due to capacitive discharge. The working element is thrust forward and electrical current is applied as it retracts back to itself, thereby cutting a groove in the tissue. This process is repeated with the cutting of multiple grooves in the tissue.
U.S. Pat. No. 4,069,667 discloses a modification to a HF resectoscope with an insulating extension to the tube surrounding the telescope This modification prevents arcing from the cutting loop to the telescope, with injury to the surgeon.
U.S. Pat. No. 4,362,160 discloses a unipolar cutting loop having a vertical cutting surface which is used in an insulating tube. The tube has triangular or rectangular cut outs which allow the cutting of a wedge shaped meniscus in a joint without touching other tissue. Cutting is achieved by a back and forth motion.
U.S. Pat. No. 5,133,713 discloses a high resistivity loop electrotome heated by high voltage current and which is spun by a motor in an endoscope. Alternatively, a non-electric knife can be used. The tissue to be resected, for example a prostate, is removed by through multiple shavings by a spinning knife. The size of the loop is fixed.
U.S. Pat. No. 5,437,665 discloses unipolar HF electrodes which are spring mounted and which extend from a sheath, thereby exposing the cutting surfaces. The electrodes form a gap which is used to encircle the point of interest which is dragged through the base of the instrument.
U.S. Pat. No. 5,611,803 a tissue segmentation device in which an excised tissue is placed in a bag containing electrodes which may be heated. Heating the electrodes results in cutting of the tissue into smaller pieces which may be conveniently removed from the body cavity without enlarging the access hole.
U.S. Pat. No. 5,971,994 discloses a HF loop electrode snare used with a gastroscope whose size is adjustable by drawing the loop into or out of a guide channel or tube. The loop is used to engulf tissue to be resected with application of electrical heating at the end of the cutting action.
U.S. Pat. No. 6,416,513 discloses a configurable electrode instrument for peeling of epithelium of ectocervix. The curved configuration of the cutting surface is altered and adjusted by extending or retracting a distal end of a probe to which one end of the electrode is attached.
None of the prior art discloses the properties of the present invention, that of a laparoscopic electrotome with an adjustable-sized cutting loop which is placed adjacent to the tissue to be resected, the loop electrically heated, and the loop rotated, thereby resecting the desired portion of the tissue, while simultaneously cauterizing the tissue with prevention of excessive bleeding. The resected tissue then is grasped using the electrotome mid removed from the body through a trocar for subsequent pathological examination.